Gabapentinoids and Fetal Development: What Pregnant Women Need to Know Now

When a woman is pregnant and struggling with chronic pain, anxiety, or nerve-related conditions, the question isn’t just what medication to take-it’s whether taking it is safe for the baby. Gabapentin and pregabalin, commonly known as gabapentinoids, have become go-to treatments for these issues. But as their use in pregnancy has surged-rising from 0.2% of pregnancies in 2000 to nearly 4.2% today-the evidence about their impact on fetal development is finally catching up. And what we’re learning isn’t simple.

What Are Gabapentinoids, and Why Are They Used in Pregnancy?

Gabapentin and pregabalin were originally designed to treat seizures, but today they’re prescribed far more often for nerve pain, fibromyalgia, and even anxiety. In pregnancy, they’re frequently used to manage conditions that don’t respond to safer alternatives. A woman with severe sciatica, diabetic neuropathy, or post-surgical nerve pain might find relief with gabapentin when acetaminophen or physical therapy just aren’t enough. That’s why prescriptions have climbed so sharply.

These drugs cross the placenta easily. Studies show gabapentin reaches the fetal bloodstream and even the brain tissue. Its small molecular size and water solubility mean it doesn’t get blocked by the placental barrier. If a mother takes it three times a day, the baby is exposed, too. That’s not a guess-it’s measured in blood samples from umbilical cords and confirmed in lab studies using fetal tissue models.

Major Birth Defects: The Big Picture

One of the first things doctors look for is major congenital malformations-heart defects, cleft palate, limb abnormalities. The largest study to date, published in PLOS Medicine in 2020 and tracking over 1.7 million pregnancies, found no major increase in overall birth defects from gabapentin use. The risk was almost identical: 3.21% in exposed babies versus 3.00% in unexposed. That’s reassuring.

But here’s where it gets tricky. That same study found a small but consistent signal for specific heart defects-conotruncal abnormalities like tetralogy of Fallot and transposition of the great arteries. The risk went up by about 40% (RR=1.40). For context: in unexposed pregnancies, this type of defect occurs in about 0.59% of babies. With consistent gabapentin use, it rose to 0.82%. That’s still rare, but it’s a real difference. And it wasn’t seen with lamotrigine, a safer alternative for epilepsy and mood disorders.

Pregabalin has even fewer data, but animal studies show clear developmental toxicity. The European Medicines Agency now warns against its use in pregnancy unless absolutely necessary. The FDA still labels both drugs as Category C-meaning risk can’t be ruled out.

Preterm Birth, Low Birth Weight, and NICU Admissions

The biggest red flags aren’t about birth defects-they’re about what happens after birth.

A 2020 study found that women who took gabapentin during pregnancy were 34% more likely to deliver early (before 37 weeks). They were also 22% more likely to have a baby smaller than expected for gestational age. And the most striking finding? Babies exposed to gabapentin until delivery were over 4 times more likely to need NICU care.

In one group of 209 women, 37.7% of babies born to those who took gabapentin until birth ended up in the NICU. In the comparison group-women who didn’t take it-only 2.9% did. That’s not a coincidence. The reasons? Babies showed signs of withdrawal: jitteriness, poor feeding, excessive crying, and breathing trouble. It’s not full-blown neonatal abstinence syndrome like with opioids, but it’s close enough to be dangerous.

These outcomes were strongest when gabapentin was taken in the third trimester. That’s when the baby’s nervous system is rapidly developing and most vulnerable. Even if the drug didn’t cause a structural defect, it may have disrupted how the baby’s brain and lungs matured.

What About the Baby’s Long-Term Brain Development?

Here’s where things get even more concerning-and less understood.

A 2022 study from China looked at how gabapentin affects developing brain cells in the lab. At therapeutic doses, it reduced the growth of dopamine-producing neurons by over 40%. These are the same cells that help regulate movement, mood, and reward. The drug also lowered levels of three critical genes-Nurr1, En1, and Bdnf-that are essential for brain development. Damage here might not show up at birth, but it could show up later: delays in walking, speech, attention, or emotional regulation.

That’s why the NIH is funding a major long-term study tracking 1,200 children exposed to gabapentin in the womb through age five. Results won’t be ready until late 2025, but if even a small number show subtle neurodevelopmental delays, it could change how we think about these drugs forever.

Who Should Still Take Gabapentin During Pregnancy?

This isn’t a blanket “don’t take it” warning. For some women, the risks of not taking it are worse.

Imagine a woman with severe neuropathic pain after spinal surgery. She can’t walk, sleep, or care for her older children. Her painkillers don’t work. Antidepressants make her nauseous. Physical therapy isn’t helping. Gabapentin is the only thing that gives her relief. In cases like this, the American College of Obstetricians and Gynecologists says the benefits may outweigh the risks.

But there’s a big difference between “sometimes necessary” and “commonly prescribed.” Right now, over 40% of gabapentin use in pregnancy is for pain-not epilepsy. That means many women are taking it for conditions that aren’t life-threatening. And that’s where the risk-benefit balance tips.

Doctors should ask: Is this the only option? Could we try acupuncture, physical therapy, or a different medication like duloxetine? Is the dose the lowest possible? Is it stopped before delivery?

What Should You Do If You’re Pregnant and Taking Gabapentin?

Don’t stop suddenly. Abruptly stopping gabapentin can cause seizures, anxiety spikes, or worsening pain. Talk to your doctor. Here’s what to do:

• If you’re in your first trimester and taking gabapentin for epilepsy or severe nerve pain: discuss switching to a safer alternative like lamotrigine or carbamazepine if possible.
• If you’re taking it for chronic pain: ask whether non-drug options (nerve blocks, TENS units, physical therapy) can be tried first.
• If you’re in your third trimester: talk about tapering off before delivery to reduce NICU risk. This should be done slowly over weeks, not days.
• If you’re planning pregnancy: have this conversation before you conceive. Many women don’t realize they’re pregnant until after the first trimester.
• Ask for a fetal echocardiogram if you’ve taken gabapentin regularly after 20 weeks. It’s a simple scan that can catch heart defects early.

What’s Changing Right Now?

The rules are shifting fast. In 2024, the FDA ordered all gabapentinoid manufacturers to track at least 5,000 pregnancy outcomes by 2027. That means more data is coming-and soon.

The British National Formulary now says gabapentin should only be used “if benefits clearly outweigh risks.” The European Medicines Agency has flagged pregabalin as especially risky. And the Society of Obstetricians and Gynaecologists of Canada says some clinicians are still using it because they have no better options-but they’re not happy about it.

Meanwhile, prescriptions are still climbing. Gabapentin is now the 9th most prescribed drug in the U.S. overall. That’s a problem when we know it’s being used for conditions that aren’t emergencies.

Bottom Line: It’s Not Black and White

Gabapentinoids aren’t the same as thalidomide or valproic acid. They don’t cause massive spikes in birth defects. But they aren’t harmless, either. The risks are subtle, delayed, and dose-dependent.

If you’re pregnant and taking gabapentin or pregabalin, don’t panic. But do act. Talk to your doctor. Ask about alternatives. Ask about tapering. Ask about fetal scans. And if you’re not pregnant yet but planning to be-have this conversation now. The safest choice isn’t always the easiest one. But for your baby’s future, it’s worth the effort.